In one of my latest blog posts, I talked about how to assess your seeds to find out whether they were duds before planting time. Writing about that topic piqued my interest in finding out more, so I did some research and found a great chart that garden guru Margaret Roach posted on her always informative Web site. Here is the link: http://awaytogarden.com/estimating-viability-how-long-do-seeds-last.

Roach compiled the chart based on seed viability estimates from four sources: extension services in Iowa and Vermont, Johnny’s Selected Seeds catalog, and the Fedco seed catalog. She notes in her post that it’s no wonder we all get confused about how long seeds last. Depending on the source, for example, tomato seeds can last anywhere from four to ten years. Her post, and the chart, are definitely worth a look.

Who among us has not encountered at least one person (not always a gardener) who wags a judging finger when we admit our gardens include both native and non-native (also called exotic) plants? This natives-only stance is not only annoying, it’s also wrong-headed.

What’s the difference between a native and non-native plant? Plants that are native to North America have evolved and grown over thousands of years in a specific region before European settlement. Non-native or “exotic” plants, on the other hand, have been introduced in one way or another to an area in which they did not naturally grow.

Walk through any garden center, and while you may see a few native plants, what you’ll mostly encounter are exotics that have been bred and cultivated to offer benefits like bigger or longer-lasting blooms, disease resistance, or standout color.

Many gardeners, including me, love non-native plants because of the diversity they bring to the garden. This doesn’t mean we exclude natives, but we do have a mix of plants, and maybe even a preponderance of non-natives at home. As interest in natives has grown in recent years, so has their availability, as well as the debate over which plants are the best choice for home gardens. This debate is more complex than it seems, with some of the arguments breaking down as follows:

Native plants are more pest and disease resistant than exotics. This is true in the sense that native plants are better able to withstand attacks from native pests and pathogens. But they don’t fare any better than exotics when faced with terrors like emerald ash borer, Dutch elm disease, Asian longhorned beetle, and white pine blister rust.

Native plants are more drought resistant, so they can be grown more sustainably than non-native plants. This is true when natives are planted in places that offer the conditions they need to thrive. If you’ve got the perfect spot for a native prairie garden, by all means, plant one. But plant a native sugar maple in a sandy spot and it won’t be around to enjoy for long, since it needs loamy clay soil.

Native plants offer better habitat and sustenance for insects, birds, butterflies, and wildlife. Again, there is truth here. Over time, all of these creatures have adapted to use what native plants offer. This discounts the fact, though, that many non-native species offer the same bounty, cover, and protection. What is truly at issue, some ornithologists say, is whether more and more birds that used to migrate are now sticking around to snack on the offerings of non-native plants when, sadly, some of these plants don’t offer seeds and berries with enough fats and nutrients to sustain birds through the winter. The birds may eat heartily, but it won’t be enough to keep them going through the long, harsh months so they don’t make it until spring.

Non-native plants are invasive. People often lump non-native species in with invasive plants that take over landscapes, destroying ecosystems and choking out native plants. In truth, only a small number of non-native species are invasive—think kudzu, which is taking over the south.

Rather than taking sides on this debate, it seems more prudent to accept that both native and non-native plants have characteristics that endear and alienate gardeners. Though it can’t be qualified with research or backed up by studies, one of the best plain-and-simple reasons gardeners include non-natives in their landscapes is because they like them. Gardeners who limit themselves to natives miss out on the benefits of centuries of plant cultivation and innovation. Plants like gardenia, evergreen azaleas, Japanese maples, and Norway spruce are well-behaved, non-native species that look great in the garden and perform well in the right circumstances.

Of course, no gardener should knowingly plant an invasive species. Before adding something new to your garden, check with your local extension service to get a list of plants considered to be invasive in your area. You’ll find a list of extension services here: http://www.nifa.usda.gov/Extension/index.html. If you don’t have an extension service, check the Nature Conservancy’s Web site for detailed information on invasive plants: http://www.nature.org/initiatives/invasivespecies

This spring, a red oak tree someone planted decades ago on the southern most edge of our yard is coming down. Hollow to the point of being hazardous, city arborists sprayed it with an orange X last fall. Once the snow melts, I imagine it won’t be long before they’re back armed with chainsaws and a bucket truck.

The city is removing the tree because it’s so close to the sidewalk, it falls under their jurisdiction rather than ours as property owners. As happy as we are not to be out the thousands of dollars it was going to cost to have it cut down, it’s sad that the very location that spared our wallets is probably largely to blame for that beautiful tree’s early demise.

It’s that time of year when the mailbox is full to bursting with plant and seed catalogs. If you’re thinking of ordering some bare-root perennials, great! They are a wonderful way to add plants to your garden without busting your budget. They can sometimes be a little temperamental, though, so let me offer a few tips for success.

When your plants arrive, open the box right away so you can inspect everything. Bare-root perennials are usually shipped in small plastic baggies filled with sawdust or a bit of peat moss. Roots should be white and firm. If you’re looking at plants that are yellowish or brown, or if they feel dried up or mushy, send them back for a refund. It’s not worth planting anything in that shape.

Snow doesn’t always lead to snow mold, but this year’s heavy, lasting snowfall that started before the ground froze in many parts of the country means it will definitely be showing up in a lot of yards this year.

If you haven’t heard of snow mold, it’s a fungal disease that becomes visible in spring as the snow melts. There are a couple of different types of snow mold. Gray snow mold is caused by a fungus called Typhula blight, and pink snow mold is caused by the fungus Microdochium nivalis. The fungi overwinter in infected plant debris—though gray snow mold can also survive in the soil—and they start growing during the winter underneath their cover of snow.

You know you have snow mold when you see circular, beige-colored patches in your lawn in the spring. As long as the grass stays wet and cold, those patches will keep getting bigger. These patches will look matted and may have patches of fungal growth. Gray snow mold can be anywhere between white and gray and pink snow mold will be white to pink. You may even see some mushrooms popping up in spots.

Though it looks horrible, damage from snow mold is usually just temporary. Gray snow mold stops growing once temperatures reach 45°F or the soil surface dries out. Pink snow mold, though, may flare up in wet weather if temperatures are between 32°F and 60°F.

If you have snow mold in your lawn, rake the affected patches gently to help loosen up matted areas and promote drying. Those areas should green up fairly quickly as the weather warms up.

Hi. My name is Meleah Maynard and I garden in crazy-ass cold, zone 4 Minneapolis, Minnesota. My first book, co-authored with Jeff Gillman, Decoding Gardening Advice: The Science Behind the 100 Most Common Recommendations, was recently published by Timber Press. Click here to email Meleah.